Field of the Invention
The present disclosure generally relates to image processing and, more particularly, to an image processing apparatus, an image processing method, and a medium.
Description of the Related Art
A technique of detecting edges of characters and lines of an input image has been widely used. Furthermore, an image processing apparatus which performs an image process (such as a black monochromatization process) of enhancing reproducibility of edges on pixels determined to correspond to edges of characters or lines as a result of detection of the edges of characters or lines and which does not perform the image process on other pixels has been widely used (refer to Japanese Patent Laid Open No. 11-55503). By this, an image having clear edges of characters or lines is obtained.
However, even when a pixel is determined to correspond to an edge of a character or a line, the image process is not required to be performed on the pixel in some cases. Such a pixel corresponds to an edge in a mosaic image including blocks of pixels. Each of the blocks includes pixels having the same signal value. The mosaic image is generated when a picture is enlarged by a nearest neighbor method. When detection of an edge and the image process are performed on a mosaic image, a portion which is not determined as an edge of a character or a line in a picture before enlargement is determined as an edge of a character or a line after the enlargement, and therefore, the image process is performed on the portion so as to enhance reproducibility of the edge. Specifically, an internal portion of the picture to be smoothly reproduced is sharply reproduced, and accordingly, unnatural image is obtained.